Here in Bahrain, adrift in the Arabian Gulf save for the connecting bridge of the King Fahd Causeway, truth is almost as precious a commodity as the black nectar harvested from below the desert.

And the creep of propaganda is never greater than when Formula One is in town.

Placemen for the government depict Sunday's Grand Prix as some form of benevolent mercy for the people, while dissidents are eager to accentuate more grisly police repression in the riot-scarred villages of Sitra and Sanabis. Reality, as ever, hovers precariously in between.

Few would dispute that the F1 cavalcade brings Bahrain's greatest exposure on the global stage. This tiny island kingdom derives international renown from little else besides its oil, its pearl-diving past, and a gold souk in the capital, Manama.

But the public relations whirl around Grand Prix week always brings an attempt to suppress a few secrets that King Hamad's regime would rather you did not see.

For not half an hour's drive beyond F1's gilded cocoon at the Sakhir circuit lies the spectre of disenfranchised youth, militants clad in balaclavas, and tear gas snaking like some malign yellow cloud through rubble-strewn streets.

Abuses

Bernie Ecclestone (pictured) contends that the Bahraini demonstrators are no different to "those complaining about Mrs Thatcher".

But the left-wing hardliners who sought to disrupt Thatcher's funeral procession yesterday were not levelling allegations of police brutality. They were not bringing claims of human rights abuses, or grievances over the glacial pace of political reforms promised in the wake of a violently crushed revolution.

In response, Ecclestone points out that he pulled Formula One out of South Africa in the age of apartheid.

But when I arrived in the Shia village of Banbar on Tuesday night, the 82-year-old was not exactly being portrayed as a broker of international peace. Instead, he was drawn on a placard shaking hands with a sheikh, blood dripping from their hands on to a gigantic dollar symbol.

As a student in the community of Al-Ahli said earlier this week: "The race brings money to the regime, which they then use to buy weapons to attack us."

The atmosphere is tense, if not quite as febrile as 12 months ago, when Force India mechanics fractionally escaped a petrol-bomb attack. But the fact that members of the 'February 14 coalition', a youth protest movement, were able to detonate a gas cylinder in a car in Manama on Sunday shows how quickly the balance can be tipped.

In Westminster, the All-Party Parliamentary Group for Democracy in Bahrain are in no doubt. They are calling for a boycott "on moral grounds", declaring that "if it went ahead, the race would allow the Bahrain government to present a false image to the world".

Shadow justice minister Andy Slaughter MP – a man infelicitously named for comment on human rights – argues: "Most democratic-minded people would be appalled if you allowed the Bahrain leg to go ahead amid the most appalling human rights violations."

Such violations continue to be alleged. Around 100 arrests have been made in Bahrain this month. Efforts by the authorities to project an impression of 'move along, no problems here' have also been heightened, with police patrol cars lining every stretch of motorway.

On the first night here, it took my driver four attempts to evade the checkpoints on the return journey to Juffair.

This driver disclosed that he earned more than enough money not to be transporting journalists behind the police cordon.

Rather, having lost a close friend in the failed 2011 insurrection, he said: "For the sake of your children, you must not let this repression happen to anybody else, for any reason."